JP7329816B2 - lighting system - Google Patents

Description

The present invention relates to lighting systems.

As a lighting device having a plurality of LEDs arranged linearly in a predetermined direction, for example, the detection position of a sensor such as a line sensor camera in inspection of various manufacturing processes such as steel plate, plate glass, food, banknotes, etc. There is known a linear illumination device that illuminates in a line according to the angle of view (see, for example, Patent Document 1).

In addition, as a lighting device having a plurality of ultraviolet LEDs arranged on a plane, for example, in various manufacturing processes for manufacturing films made of ultraviolet-curable plastic, ultraviolet rays are irradiated to harden the plastic and form the film. There is known a planar illuminating device that does so (see, for example, Patent Document 2).

JP 2007-225591 A JP 2011-079157 A

This type of illumination device is required to uniformly irradiate strong light to the light irradiation position in order to speed up and improve the accuracy of inspection, or to ensure the quality of products such as films.
Many of the former lighting devices have a length of 1 m or more, and a long one exceeds 5 m. On the other hand, in many cases, a plurality of LEDs are arranged at a pitch of several millimeters for uniform illumination. Therefore, hundreds or thousands of LEDs are arranged in one lighting device.

If a failure such as a short circuit or a decrease in luminance occurs in some of the plurality of LEDs, the accuracy of the inspection is lowered.
Hundreds or thousands of LEDs in the latter lighting device are often arranged at a small pitch. Since the light from each LED cures the photocurable plastic, if some of the LEDs fail such as a short circuit or a decrease in brightness, the quality of the product is degraded.

In order to prevent deterioration of inspection accuracy and quality of products, etc., place an illuminometer in the direction of light irradiation from the lighting device and inspect that each LED is lit normally before inspection or manufacturing. It is also possible. However, lighting devices are often installed in inspection lines and manufacturing lines, and it is difficult to accurately inspect illuminance with an illuminometer.

It is also conceivable to provide a sensor for each of the plurality of LEDs and monitor the presence or absence of failure of each LED based on the output of the sensor. However, it is not realistic to provide a sensor for each of all LEDs. Further, when the sensor and the LED are one-to-one, if the output value of the sensor decreases, it is possible that not only the LED is defective but also the detection accuracy of the sensor is degraded. In particular, when the LED emits ultraviolet light, there is concern about premature failure of the sensor when the LED is a high-brightness LED.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lighting system capable of accurately detecting a failure of an LED.

In order to solve the above problems, a lighting system according to an aspect of the present invention includes a lighting device main body, a plurality of LEDs provided in the lighting device main body, and control means capable of lighting the plurality of LEDs for each group. and wherein the control means is capable of lighting the plurality of LEDs in an inspection mode, and in the inspection mode, the control means is configured to light the plurality of LEDs group by group. The lighting system comprises a number of sensors that is smaller than the number of the groups and detects light from the LEDs, and the control means causes the plurality of LEDs to light up for each of the groups. , the output value of the sensor at that time is stored as a reference value for each group, and the control means turns on the plurality of LEDs for each group in the inspection mode, The detected value of the sensor at that time is compared with the reference value, and LED failure is determined based on the comparison result.

In this aspect, the control means lights up a plurality of LEDs for each group, the control means stores a reference value for each group, and the failure of each LED is determined using a smaller number of sensors than the group. . It is also possible to provide sensors for each group. However, if a sensor is provided for each group, the number of sensors increases, and checking the detection accuracy of the sensors is troublesome due to the large number of sensors. In particular, when the LED emits ultraviolet rays, there is concern about early failure of the sensor.

When the sensor and group are one-to-one, if the output value of the sensor drops, not only is there a possibility that some of the LEDs in the group are malfunctioning, but it is also possible that the detection accuracy of the sensor is declining. be. On the other hand, when the number of sensors is smaller than the number of groups, one sensor is in charge of two or more groups. Simultaneous LED failures in each of two or more groups are unlikely. Therefore, when the output value of the sensor for any one of two or more groups decreases, the detection accuracy of the sensor does not decrease, but it means that the LED in that group is malfunctioning. Thus, the lighting system of each of the above embodiments can accurately detect LED failures.

According to the present invention, LED failures can be accurately detected.

1 is a plan view of a lighting device of an LED lighting system according to a first embodiment of the present invention; FIG. 2 is a circuit configuration diagram for lighting LEDs of the LED lighting system of the first embodiment; FIG. 1 is a cross-sectional view of a lighting device of an LED lighting system according to a first embodiment; FIG. FIG. 2 is a cross-sectional view of the essential parts of the lighting device of the LED lighting system of the first embodiment; FIG. 2 is a cross-sectional view of the essential parts of the lighting device of the LED lighting system of the first embodiment; It is an example of a time chart of lighting control by the control device of the first embodiment. 8 is another example of a time chart of lighting control by the control device of the first embodiment; FIG. 4 is a cross-sectional view of a main part of a modification of the lighting device of the LED lighting system of the first embodiment; FIG. 6 is a longitudinal cross-sectional view of a lighting device of an LED lighting system according to a second embodiment of the present invention; FIG. 10 is a lateral cross-sectional view of a lighting device of an LED lighting system according to a second embodiment; FIG. 3 is a plan view of a substrate 10 showing a modification of the lighting device of the LED lighting system according to the first embodiment;

An LED lighting system according to a first embodiment of the present invention will be described below with reference to the drawings.
This LED lighting system irradiates a predetermined area with light to cure, for example, a photocurable resin. Note that this LED lighting system may illuminate the position detected by the inspection sensor. As shown in FIG. 2, this LED lighting system connects a lighting device 1, a power supply unit 2, and the lighting device 1 and the power supply unit 2 to supply power from the power supply unit 2 to the lighting device 1. and a connection cord 3. The connection cord 3 supplies driving power to the lighting device 1 .

The illumination device 1 has a plurality of substrates 10, and each substrate 10 has a plurality of LEDs 11 connected in series, as shown in FIGS. An FET (field effect transistor) 12 as a transistor and a current detection resistor 13 are connected to each LED substrate 10 via a connection cord 3 . The drain terminal of FET 12 is connected to the low potential end of a plurality of LEDs 11 (LED series circuit) connected in series, and the source terminal of FET 12 is connected in series with current detection resistor 13 .

In this embodiment, the FET 12 is connected to the low potential end of the LED series circuit, but it is also possible to connect the FET 12 to the high potential end of the LED series circuit. In this case, the source terminal of FET 12 is connected to the high potential end of the LED series circuit.

Each LED board 10 has a high potential side power supply section 14a connected to the high potential end of the DC power supply D of the power supply unit 2 via the connection cord 3, and a low potential side power supply section 14b connected to the FET 12. and

As shown in FIGS. 1 and 2, the power supply unit 2 has one or a plurality of light control boards 20, and each light control board 20 controls the light of the plurality of LED boards 10 one by one. It is configured. Although the light control board 20 is provided in the power supply unit 2 in this embodiment, the light control board 20 may be provided in the lighting device 1 . A dimming signal supply unit 30 that supplies a dimming signal to each dimming substrate 20 is provided in the power supply unit 2, and the dimming signal supply unit 30 sets the amount of current to be supplied to each of the plurality of LED substrates 10. can do. For example, the dimming signal supply unit 30 transmits to each dimming substrate 20 a dimming signal for each LED substrate 10 according to information input by the operator to the input unit 40 of the power supply unit 2 .

Each dimming board 20 supplies the received dimming signal to the reference potential input section 21b of each operational amplifier 21 via a D/A converter (not shown). That is, each dimming board 20 supplies the reference potential based on the dimming signal from the dimming signal supply part 30 to the reference potential input part 21 b of the operational amplifier 21 corresponding to each LED board 10 .
Since it is configured in this way, the illumination position just below the end of the plurality of LEDs 11 arranged in parallel and the illumination position just below the center of the plurality of LEDs 11 arranged in parallel are adjusted so that the amount of light is the same. is possible. In addition, even if there is variation in the light intensity of each LED 11 due to manufacturing factors or the like, it is possible to make adjustments to reduce variations in the light intensity at the illumination position.

The output terminal 21 c of the operational amplifier 21 is connected to the gate terminal of the FET 12 , and the comparison potential input section 21 a of the operational amplifier is connected between the source terminal of the FET 12 and the current detection resistor 13 on the LED substrate 10 .

As shown in FIG. 2, a well-known constant current circuit having an FET 12, a current detection resistor 13, and an operational amplifier 21 is constructed. In this constant current circuit, the FET 12 supplies a drive current from the DC current device D to the connected LED series circuit. In addition, by this constant current circuit, the potential of the high potential side of the current detection resistor 13 changes according to the potential of the reference potential input section 21b of the operational amplifier. It is possible to control the flowing current (adjust the light amount of each LED 11). A constant voltage circuit may be used instead of the constant current circuit.

Since it is comprised as mentioned above, the power supply unit 2 of this embodiment can make several LED11 light for every group. Specifically, in this embodiment, the power supply unit 2 can turn on the LED 11 for each board 10 .

Each LED board 10 is made of, for example, an aluminum plate, and is fixed to a heat sink 72a provided in the illumination device main body 71 and extending along the board 10 so as to come into surface contact therewith. In this embodiment, as shown in FIG. 3 , a lower heat sink 72 b to which a heat sink 72 a is fixed is fixed to the lighting device main body 71 . The illumination device main body 71 is composed of a lower body 71a to which the lower heat sink 2b is fixed, a plurality of side plates 71b whose lower ends are fixed to the ends of the lower body 71a, and the lower body 71a and the side plates 71b. and a cover (transparent plate) 80 covering the upper end side of the formed space. The cover 80 is made of translucent material such as acrylic plastic or glass. The heat sink 72a and the lower heat sink 72b may be of an air-cooling type, but a water-cooling type can perform cooling without being influenced by the surrounding environment.

This illumination device 1 is provided with a sensor 90 capable of detecting the amount of light at the end of the cover 80 . As the sensor 90, a photodiode, a photometer, or the like that can detect the amount of light can be used. The detection result of the sensor 90 is transmitted to the control device (control means) 100 of the power supply unit 2 .

A plurality of substrates 10 are provided with fewer sensors 90 than the number of substrates 10 concerned. In this embodiment, two sensors 90 are provided for twelve substrates 10 . One of the two sensors 90 is arranged on one end side of the cover 80 and detects light emitted from the one end of the cover 80 . The other of the two sensors 90 is arranged on the other end side of the cover 80 and detects light emitted from the other end of the cover 80 .
In this embodiment, as shown in FIG. 1, the direction in which the LEDs 11 are arranged side by side between one end and the other end of the cover 80 may be referred to as the X direction. The direction is sometimes referred to as the Y direction.

In this embodiment, one surface in the thickness direction of the cover 80 is an incident surface 80a on which light from the LED 11 is incident, and the other surface in the thickness direction is an output surface 80b from which light is emitted. A plurality of reflecting portions 81 are provided on the cover 80 . Each reflecting portion 81 is, for example, a concave portion provided in the exit surface 80b. In this embodiment, the recess has four inclined surfaces. As shown in FIG. 5, two of the four inclined surfaces 81a and 81b are arranged in the X direction, and the other two inclined surfaces are arranged in the Y direction. In one example, the recess has a pyramidal shape.

The two inclined surfaces 81a and 81b aligned in the X direction are approximately triangular or triangular, respectively, and the two inclined surfaces aligned in the Y direction are also approximately triangular or triangular. Each of the two inclined surfaces 81a and 81b aligned in the X direction may be substantially trapezoidal or trapezoidal, and each of the two inclined surfaces aligned in the Y direction may be substantially trapezoidal or trapezoidal. In this embodiment, as shown in FIG. 5, the angle β formed between the inclined surfaces 81a and 81b and the output surface 80b is 30°. The angle β may be another angle as long as the functions described later are satisfied.

As shown in FIG. 4 , each reflector 81 corresponds to a plurality of LEDs 11 . As shown in FIG. 1 , in this embodiment, each reflecting portion 81 is arranged at the center position of the four LEDs 11 when viewed from the optical axis LA direction of the LEDs 11 . In addition, in this embodiment, three reflecting portions 81 are arranged for the twelve LEDs 11 on one substrate 10 in plan view. In addition, the reflection part 81 may be arrange|positioned in the central position of three LED11, the central position of two LED11, the central position of five LED11, or the central position of six LED11.

As shown in FIGS. 4 and 5, the surfaces 81a and 81b reflect light from the corresponding LEDs 11 in the X direction. That is, the surfaces 81 a and 81 b reflect the light from the corresponding LEDs 11 toward the sensor 90 .

As shown in FIG. 5, light that forms an angle α with the optical axis LA of the LED 11 enters the surfaces 81a and 81b. It is preferable that the angle obtained by adding the angle β to the angle α is equal to or greater than the critical angle of the material of the cover 80 . If the refractive index of the material forming the cover 80 is approximately 1.5, the critical angle is approximately 42°. Since the angle β is 30° in this embodiment, the light from the LED 11 forming an angle of 12° or more with the optical axis LA is totally reflected by the surfaces 81a and 81b.
It should be noted that the total reflection is not necessarily required. Even if the angle obtained by adding the angle β to the angle α is less than the critical angle of the material of the cover 80 , part of the light incident on the inclined surfaces 81 a and 81 b is reflected toward the sensor 90 .

The control device 100 is, as shown in FIG. 2, a computer having a processor 110, a storage unit 120, a RAM, etc., an integrated circuit having the same functions as the computer, or the like.

The storage unit 120 stores a lighting program 120a and a set of reference values 120b. The lighting program 120 a is for causing a set current to flow through each substrate 10 . The lighting program 120a causes a set current to flow through each substrate 10, as shown in the time chart shown in FIG. 6, for example.

The storage unit 120 stores a reference value 120b for each of the plurality of substrates 10. FIG. The reference value 120b may be created based on a reference creation program 120c stored in the storage unit 120. FIG. For example, the processor 110 illuminates the LED 11 for each substrate 10 based on the reference creation program 120c, and detects the detection values of the two sensors 90 provided corresponding to the substrate 10 that has been illuminated. 10, and stored in the storage unit 120 as a reference value 120b. The detection values of the two sensors 90 may be stored separately in the storage unit 120 , or the average value, added value, or the like of the detection values of the two sensors 90 may be stored in the storage unit 120 . The identification information of the substrate 10 may be the number of the substrate 10, positional information, and the like.

The illumination device 1 or the power supply unit 2 may be provided with an operation section such as a button 41 for starting reference setting. In this case, the processor 110 may measure the reference value 120b described above and store it in the storage unit 120 according to the operation of the operation unit. Alternatively, the processor 110 may measure the reference value 120b and store it in the storage unit 120 according to a predetermined signal from an external computer such as a tablet computer. Since the reference value 120b may change depending on the environment in which the lighting device 1 is arranged, the setting of the reference value 120b according to the operation of the operation unit or the signal from the computer is necessary for accurate failure detection of the LED 11. Advantageous.

Based on the lighting program 120a, the processor 110 lights the LEDs 11 in the inspection mode while the plurality of substrates 10 are emitting light, as shown in FIG. As shown in FIG. 6, the processor 110 turns on the LEDs 11 of the plurality of substrates 10 for a predetermined lighting period L1, and then turns off the LEDs 11 for a predetermined lighting period L2. The processor 110 simultaneously turns on and off the multiple substrates 10 .

The processor 110 performs lighting in the inspection mode based on the lighting program 120a while performing the lighting and extinguishing described above. Lighting in the inspection mode is performed during the light-out period L2. Also, the lighting in the inspection mode is performed by lighting the plurality of substrates 10 one by one as shown in FIG. 6, for example. In FIG. 6, the processor 110 selects No. during the first turn-off period L2. Only the substrate 10 numbered 1 is turned on, and the numbered substrate 10 is turned on during the second turn-off period L2. Only the substrate 10 numbered 2 is turned on, and the number No. 2 is turned on during the third turn-off period L3. Only the substrates 10 numbered 3 are lit, and then the substrates 10 are similarly lit one by one.

That is, the processor 110 lights the plurality of LEDs 11 in the inspection mode for each group. In addition, in the inspection mode, the processor 110 may light up a plurality of substrates 10, such as two or three. Even in this case, it can be said that the processor 110 lights the plurality of LEDs 11 for each group.

When the inspection mode is turned on, the processor 110 compares the detection values of the two sensors 90 corresponding to the board 10 that has been turned on with the reference value 120b of the board 10, and based on the comparison result, turns on the board 10. Failure determination of the LED 11 is performed. In the present embodiment, each board 10 has 12 LEDs 11, so if one of the 12 LEDs 11 fails to light due to a failure, the detected values of the two sensors 90 are 5% or more of the reference value 120b, for example. become smaller. Therefore, the comparison enables the processor 110 to determine the failure of each board 10 .

Note that in the present embodiment, the reference value 120b for each substrate 10 is stored in the storage unit 120 in advance. On the other hand, the detection value of the corresponding sensor 20 when each board 10 is lit in the inspection mode may be stored in the storage unit 120 as the reference value 120b of each board 10 . In this case, when the reference value 120b is created, the illumination device 1 is placed in an environment in which it is actually used, and there is also an object to which the illumination device 1 emits light. Therefore, the reference value 120b becomes more accurate.

Alternatively, as shown in FIG. 7, the inspection mode lighting may be performed by keeping the target substrate 10 lit during the extinguishing period L2. Even in this case, it is possible to create the reference value 120b. Also, in this case, even if the light-out period L2 is short, the amount of light emitted from the LED 11 in the inspection mode is stable. If the amount of light irradiation is important, the shorter the light-off period L2, the better. For example, the light-out period L2 may be several microseconds. It may be difficult to turn on the LED 11 in the inspection mode and then turn off the LED 11 in such a short time. In such a case, lighting in the inspection mode as shown in FIG. 7 is advantageous for stabilizing the light irradiation amount of each LED 11 in the inspection mode.

Also, as shown in FIG. 8, a shutter 91 may be provided to block the exposed portion of the sensor 90 . As the shutter 91, for example, an electronic shutter such as a well-known focal plane shutter, lens shutter, electronic front curtain shutter, rolling shutter, or the like can be used. Based on the lighting program 120a, the processor 110 controls the shutter 91 so that the shutter 91 is closed during the lighting period L1 and opened during the lighting period L2. The processor 110 may open only the shutter 91 of the sensor 90 corresponding to the substrate 10 to be lit in the inspection mode during the extinguishing period L2.

This configuration prevents the sensor 90 from deteriorating due to the sensor 90 being irradiated with a large amount of light from all the LEDs 11 during the lighting period L1. In particular, when each LED 11 emits ultraviolet light, or when each LED 11 is a high-brightness LED, deterioration of the sensor 90 is effectively prevented by the shutter 90 .
Sensor 90 may be housed in case 92 and sensor 90 may be covered by case 92 and shutter 91 . In this case, deterioration of the sensor 90 is more effectively prevented.

An LED lighting system according to a second embodiment of the present invention will be described below with reference to the drawings.
This LED lighting system uses an illumination device 4 for linear illumination, as shown in FIGS. 9 and 10, instead of the illumination device 1 for planar illumination of the first embodiment. This LED lighting system has the same power supply unit 2 and connection cord 3 as in the first embodiment. The same reference numerals are given to the same configurations as in the first embodiment, and the description thereof will be omitted.

The lighting device 4 has a plurality of substrates 10, and each substrate 10 has a plurality of LEDs 11 connected in series. The connection between the power supply unit 2 and each board 10 is the same as in the first embodiment. Therefore, even in the second embodiment, the power supply unit 2 can turn on the plurality of LEDs 11 for each group, for example, for each board 10 .
The illumination device 4 is provided with a sensor 90 capable of detecting the amount of light at the end of the cover 80 , and the detection result of the sensor 90 is transmitted to the control device 100 of the power supply unit 2 .

Also in the second embodiment, the number of sensors 90 smaller than the number of substrates 10 is provided for a plurality of substrates 10 . Specifically, the lighting device 4 is provided with one sensor 90 at each end in the direction in which the LEDs 11 are arranged side by side, and the lighting device 4 has three or more substrates 10 . Each sensor 90 detects light emitted from the edge of the cover 80 . In the second embodiment, as shown in FIG. 10, the direction in which the LEDs are arranged may be referred to as the X direction, and the direction in which the cover 80 extends perpendicular to the X direction may be referred to as the Y direction. be.

As shown in FIGS. 9 and 10, the illumination device 4 is provided with a condensing lens 4a for condensing light from the plurality of LEDs 11 in the Y direction. Further, as shown in FIGS. 9 and 10, a diffusion plate 4b for diffusing the light from the plurality of LEDs 11 may be provided. The light passes through the cover 80 after passing through the condenser lens 4a. The diffusion plate is made of transparent plastic, glass, or the like. Note that the condensing lens 4a and the diffusion plate 4b may be omitted.

A plurality of reflecting portions 81 similar to those in the first embodiment are provided on an emission surface 80b from which light from the LED 11 that has passed through the condensing lens 4a, the diffuser plate 4b, etc. is emitted, and the plurality of reflecting portions 81 are arranged in the X direction. I'm in.
As shown in FIG. 10, each reflecting portion 81 reflects light from the plurality of LEDs 11 in one or the other direction in the X direction within the cover 80, as in the first embodiment.

In the second embodiment as well, the storage unit 120 stores the reference value 120b for each of the plurality of substrates 10, similarly to the first embodiment or its modification.
Also in the second embodiment, the processor 110 turns on the LED 11 of each board 10 during the lighting period L1 and turns off the LED 11 during the lighting period L2 as shown in FIGS. Further, as in the first embodiment, the processor 110 turns on the plurality of substrates 10 one by one in the inspection mode during the extinguishing period L2, and the detection values of the two sensors 90 at that time are the reference values of the substrate 10. Compare with 120b. Further, the processor 110 performs failure determination of each board 10 based on the comparison result.
Thus, in the second embodiment, as in the first embodiment, it is possible to accurately determine failure of each substrate 10 during use of the lighting device 4 .

In addition, in 1st Embodiment and 2nd Embodiment, the reflection part 81 may be abbreviate|omitted. Even in this case, for example, if the cover 80 is a diffusion plate and the incident surface 80a of the cover 80 is provided with irregularities for diffusion, part of the light from each LED is reflected by the output surface 80b. , some of the reflected light reaches the sensor 90 . When adopting such a cover 80 in the second embodiment, the diffusion plate 4b can be omitted. Also, the light from the LED 10 may reach the sensor 90 at the edge of the cover 80 by other methods.
Further, a sensor 90 may be provided at the end of the condenser lens 4a, and the sensor 90 may detect light from the end of the condenser lens 4a.

Further, in the first embodiment and the second embodiment, the reflecting section 81 may be omitted and each sensor 90 may be provided on the substrate 10 . For example, as shown in FIG. 11, a sensor 90 may be arranged at the central position of the four LEDs 11. FIG. Even in this case, fewer sensors 90 than the number of substrates 10 are provided for the plurality of substrates 10 . In addition, the sensor 90 may be arranged at the central position of the three LEDs 11 , the central position of the two LEDs 11 , the central position of the five LEDs 11 , or the central position of the six LEDs 11 .
Also in this case, the storage unit 120 stores the reference value 120b for each of the plurality of substrates 10, as in the first embodiment or its modification.

Then, the processor 110 turns on the LED 11 of each substrate 10 during the lighting period L1 and turns off the LED 11 during the lighting period L2 as shown in FIGS. Further, as in the first embodiment, the processor 110 turns on the plurality of substrates 10 one by one in the inspection mode in the extinguishing period L2, and detects the detection values of the corresponding three sensors 90 at that time. Compare with reference value 120b. Therefore, as in the first and second embodiments, it is possible to accurately determine the failure of the LED 11 of each board 10 during use of the lighting device 1 .

In each of the above-described embodiments, the plurality of LEDs 11 are lit during the lighting period L1, and the inspection mode is lit during the lighting period L2 during which the plurality of LEDs 11 are extinguished. On the other hand, the lighting devices 1 and 4 can be turned on in the inspection mode before and after the lighting devices 1 and 4 are not in use. For example, the substrates 10 of the lighting devices 1 and 4 are lit one by one before and after curing of the photocurable resin using the lighting devices 1 and 4 and inspection in the inspection process. By comparing the detected value of the sensor 90 at that time with the reference value 120b, it becomes possible to accurately determine the failure of the LED 11 of each board 10. FIG. In this case, instead of intermittently lighting the plurality of LEDs 11 during the light-out period L2, it is possible to keep them lit without turning them off.

In each of the embodiments described above, each reflecting portion 81 has a pyramid shape, but each reflecting portion 81 may have a dome shape. Each reflecting portion 81 may have another shape as long as it reflects part of the light from the corresponding LED 11 toward the sensor 90 .

It should be noted that, in each of the above-described embodiments, it is also possible to provide the sensor 90 at other locations within the illumination devices 1 and 4 . Alternatively, it is also possible to provide the sensor 90 outside the lighting devices 1 and 4 . Even in these cases, if the reference value 120b of each substrate 10 is stored in the storage unit 120, each substrate can be detected by comparing the detection value of the sensor 90 with the reference value 120b when each substrate 10 is lit in the inspection mode. It is possible to accurately determine the failure of the 10 LEDs 11 .

Note that in each of the above-described embodiments, the reference value 120b is stored in the storage unit 120 of the control device 100, and the detection value of the sensor 90 is transmitted to the control device 100. FIG. On the other hand, the reference value 120b is stored in the storage unit of another control device which is a computer, the detection value of the sensor 90 is transmitted to the other control device, and the other control device controls each substrate 10 based on the reference value 120b. A failure of the LED 11 may be determined. In this case, control device 100 and other control devices function as control means.

In each of the above embodiments, the control device 100 turns on the plurality of LEDs 11 for each group, the control device 100 stores the reference value 120b for each group, and each LED 11 failure is determined. It is also possible to provide sensors 90 for each group. However, if the sensors 90 are provided for each group, the number of sensors 90 increases, and checking the detection accuracy of the sensors 90 is time-consuming because of the large number of sensors 90 . In particular, when the LED 11 emits ultraviolet rays, the sensor 90 may fail at an early stage.

When the sensor 90 and the group are one-to-one, if the output value of the sensor 90 decreases, not only is there a possibility that some of the LEDs 11 in the group are defective, but also the detection accuracy of the sensor 90 is decreased. It is possible. On the other hand, when the number of sensors 90 is smaller than the number of groups, one sensor 90 is in charge of two or more groups. It is unlikely that failures of the LEDs 11 will occur simultaneously in each of two or more groups. Therefore, when the output value of the sensor 90 for any one of two or more groups decreases, the detection accuracy of the sensor 90 is not degraded, but the LED 11 of that group is faulty. . Thus, the lighting system of each of the above embodiments can accurately detect the failure of the LED 11 .

Further, in each of the above-described embodiments, the sensor 90 is arranged so as to detect light from the edge of the transparent plate. Therefore, the sensor 90 will not reduce the amount of light for illumination of the lighting devices 1 and 4 in the future. In addition, when the illumination devices 1 and 4 are ultraviolet illumination or high-brightness illumination, the sensor 90 is prevented from failing early because the sensor 90 is not directly irradiated with strong light in the illumination range.

Further, in each of the above-described embodiments, since the light exit surface 80 b of the cover 80 is provided with the reflecting portion 81 , part of the light from the LED 11 can be efficiently directed to the end portion of the cover 80 . This is advantageous in accurately determining failure of the LED 11 based on the detected value of the sensor 90 .

Further, in each of the above-described embodiments, the control device 100 repeats turning on the plurality of LEDs 11 during the lighting period L1 and turning off the LEDs 11 during the turning off period L2. In addition, the control device 100 turns on the plurality of LEDs 11 in the inspection mode for each group during the extinguishing period L2. Therefore, it is possible to check whether or not each LED 11 is faulty while lighting is being performed by the lighting devices 1 and 4 . This is advantageous in ensuring the quality of products manufactured or inspected using the illumination devices 1,4.

In each of the above embodiments, the reflecting portion 81 is arranged at the center position of the plurality of LEDs 11 when viewed from the direction of the optical axis LA of the LEDs 11, and the influence of the light amount of each LED 11 on the detection value of the sensor 90 is approximately be equivalent. This is advantageous for accurately detecting whether or not each LED 11 is faulty.
As shown in FIG. 11 , the sensor 90 may be attached to the substrate 10 so as to be arranged at the central position of the plurality of LEDs 11 when viewed from the direction of the optical axis LA of the LEDs 11 . Even in this case, the influence of the light amount of each LED 11 on the detection value of the sensor 90 is substantially the same.

In each of the above-described embodiments, a single sensor 90 may be provided instead of the plurality of sensors 90 at the end of the cover (transparent plate) 90 or the condenser lens (transparent member) 4a. Even in this case, the same effect as described above can be achieved.

DESCRIPTION OF SYMBOLS 1, 4... Lighting apparatus, 2... Power supply unit, 3... Connection cord, 10... LED board, 11... LED, 12... FET, 13... Current detection resistor, 20... Dimming board, 21... Operational amplifier, 30... Adjustment Optical signal supply unit 40 Input unit 71 Illumination device body 80 Cover 80a Incident surface 80b Output surface 81 Reflector 90 Sensor 91 Shutter 100 Control device 120 Storage section 120b Reference value 120c Reference creation program.

Claims (7)

a lighting device body;
a plurality of LEDs provided in the main body of the lighting device;
A lighting system comprising control means capable of lighting the plurality of LEDs for each group,
The control means can light the plurality of LEDs in an inspection mode,
In the inspection mode, the control means is configured to light the plurality of LEDs for each group,
The lighting system comprises fewer sensors than the number of groups, the sensors detecting light from the LEDs;
The control means has a function of lighting the plurality of LEDs for each group and storing the output value of the sensor at that time as a reference value for each group,
The control means, in the inspection mode, lights the plurality of LEDs for each group, compares the detection value of the sensor at that time with the reference value, and determines an LED failure based on the comparison result. system. A transparent plate attached to the main body of the lighting device and through which light from the plurality of LEDs is transmitted;
One surface in the thickness direction of the transparent plate is an incident surface on which light from the plurality of LEDs is incident, and the other surface in the thickness direction is an output surface from which light is emitted,
The exit surface is provided with a plurality of reflecting portions for directing part of the light from the plurality of LEDs toward the edge of the transparent plate,
2. The lighting system of claim 1, wherein the sensor is arranged to detect light from an edge of the transparent plate. The control means is configured to repeatedly turn on the plurality of LEDs during a predetermined lighting period and turn off the LEDs during a predetermined turning-off period,
3. The lighting system according to claim 1, wherein said control means turns on said plurality of LEDs for each group during said extinguishing period. 3. The lighting system according to claim 2 , wherein said reflector is arranged at a center position of said plurality of LEDs when viewed from the optical axis direction of said plurality of LEDs. comprising a plurality of substrates on which the plurality of LEDs are mounted;
4. The lighting system according to any one of claims 1 to 3, wherein the sensor is attached to the substrate and arranged at a center position of the plurality of LEDs when viewed from the optical axis direction of the plurality of LEDs. 6. The lighting system according to any one of claims 1 to 5, wherein the plurality of LEDs are arranged in a row in an X direction perpendicular to the optical axis of the LEDs. The plurality of LEDs are provided so as to be aligned in an X direction perpendicular to the optical axis of the LEDs, and are provided to be aligned in a Y direction perpendicular to the optical axis and the X direction. Item 6. The lighting system according to any one of items 1 to 5.

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